South Dakota’s eerie green sky looks straight out of Stranger Things

When it comes to fantastical spectacles across the sky at night, there’s shooting stars, there’s the Northern Lights, and then, of course, there’s a great big green sky caused by a storm hurtling up to 99mph through the mid-West.

That’s what locals of Sioux Falls, South Dakota saw earlier this week when a derecho hit the town. If you’re not sure what a derecho is, then be not sure no longer – it’s not a new Stranger Things foe (although, come on, how much does this sky look exactly like something from the upside down?) but an intense wind storm spurred on by a series of really fast moving severe thunderstorms. Why did it cause the sky to go green?

'Thunderstorms tend to occur later in the day due to the sun's energy during the day helping to fuel them,’ Isaac Longley, a meteorologist told DailyMail.com.

'As many of us know, the sun appears redder later in the day as it approaches the horizon. However, light underneath a tall thundercloud appears blue due to the scattering by water droplets.

'When the blue light is illuminated by the red light from the setting sun, it appears green, which is why some thunderstorms have that greenish hue to it’

And the severity of this derecho is why the sky was more than a greenish hue, but a proper Grinch-coloured day-go green.

“While it is relatively common to see these green skies, especially in the Plains, the skies associated with the severe storms that pushed through Sioux Falls during the afternoon of July 5th appeared even greener than normal.” Longley continued:

“This of course caught the attention of many who had never seen skies so green. In this particular case, the green skies lasted for around 10-20 minutes as the storms approached the city of Sioux Falls.”